Frank Modruson has a thing for better, faster, cheaper. As CIO of business and IT service provider Accenture, that's what he wants to deliver to his internal customers and what they in turn promise to their clients. "I'm a big believer in technology and a big believer that technology helps the business in a lot of ways," Modruson says. "But it needs to be better, faster or cheaper. If you hit all three, it starts to get very compelling." \n\nIn the last few years, cloud computing has gotten very compelling for Accenture. \n\nModruson's first foray into the cloud was a Software-as-a-Service (SaaS) recruiting system five years ago. Today, Accenture has two dozen applications in the cloud. He's made moves to prepare the organization for infrastructure-as-a-service (IaaS), introducing a single IP network for voice and data and aggressively pursuing server, database and storage virtualization in the corporate data center. And that's just a start, he says. \n\nThe outsourcing giant's CIO (named in 2010 to CIO Magazine's CIO Hall of Fame) shared his biggest lessons learned about cloud computing with CIO.com. 1. The cloud can take you places you couldn't go before. Five years ago, Accenture had a different recruiting system in every country. In the U.S., there was a custom software system. In another country, recruiting was tracked by spreadsheet. At the time, Accenture had 90,000 employees. A total of 210,000 employees and millions of applications later, Modruson has decommissioned the IT systems in 40 countries. "We had the existing U.S. workflow and system, but going around the world and trying to implement that in 40 countries would have been kind of ludicrous," says Modruson. 2. Resistance is a given.Accenture is in the people business; recruiting is a core competency. Thus, the tendency within the firm was to think the recruiting software has to be special. "One of the nice things about SaaS is you can really push the business to say, 'What do we really need to do here?' Recruiting may be one of our secret sauces but emailing back a candidate or letting them apply online\u2014that just enables the process. The secret sauce is not the software," Modruson says. \n\nSome business users balked. They wanted all the new capabilities but the look and feel of the way they used to do things. "At a certain point, it just becomes an excuse," says Modruson. "We went through the same thing with our [traditional ERP] system." Over time, with targeted training and open communication, people will understand the new system and its benefits.3. Security is a red herring. "Security tends to be something that people focus on a lot, and they should," says Modruson. "You want your information to be secure. " The perception that something under your control is inherently more secure is misguided, he says. Is your money safer in the bank or under your mattress? Cloud vendors, because of their scale, may invest much more in security than a single enterprise ever would, Modruson says. The key is to approach cloud security diligently: test, monitor, review. (See "Four Ways to Mitigate Mobile and Cloud Data Leaks.") 4. Transformation takes time (lots of time). Modruson began the journey towards IaaS more than five years ago by rationalizing applications, blowing up the old corporate network, and doing serious data center virtualization. He's whittled down the company's application portfolio down from 2,100 systems down to 530. (The application reduction work has been going on for more than 10 years.) Accenture has virtualized more than 80 percent of its servers, 220 databases are now supported by 30 physical servers (down from 449), and physical storage has remained static even as the company's storage needs have ballooned 122 percent during the last two years. \n"If you play it out correctly it allows you to move things around from server to server without regard to specific hardware configuration," says Modruson. "That positions us not just to take costs out of our existing environment but it will allow us to move to someone else's cloud." But adoption of IaaS is still a ways in the future. "[Cloud adoption] can happen faster at smaller and mid size companies or start-ups," Modruson says.5. Your legacy systems are costlier than you think. Most enterprises Accenture's size are mired in multiple generations of software and hardware, Modruson says. "You might think [those systems are] cheap because they're totally depreciated, but they can be difficult to support. Those are like cement shoes," he says. "It makes it hard for CIOs to move forward. You have to take a look at your technology footprint and figure out how to leave your past behind." \n\n\nFollow everything from CIO.com on Twitter @CIOonline.